What a Form 4 Actually Is
The SEC Form 4 is the document corporate insiders use to tell the public they traded their own company’s stock. When a director, a named executive officer, or anyone who owns more than 10% of a company buys or sells shares, they have to file one. The form is short, but it is the raw material behind every insider-buying story you will ever read, including the one behind Michael Brush’s “I Just Found the 3 Stocks Behind $11.3 Million in Insider Buying” pitch for Cabot Insider Edge.
Brush is a veteran financial journalist who launched Cabot Insider Edge this summer after editing Cabot Cannabis Investor. His whole teaser rests on reading Form 4s correctly, so understanding the form is the fastest way to judge the pitch for yourself.
Who Has to File, and When
The filing requirement covers officers, directors, and beneficial owners above the 10% threshold. When one of them trades, they generally have two business days to submit the Form 4 to the SEC. That two-day window is what makes insider data timely in a way most other corporate disclosures are not. It also means the trades you read about are recent by construction, not a snapshot from a quarterly report that is already stale.
The form itself lists the insider’s name and title, the transaction date, the number of shares, the price, and the resulting ownership. That last column matters more than most people realize, because a large sale that leaves an executive still holding millions of shares means something different from one that cuts their position to nearly nothing.
The Codes Are the Whole Game
The most important field on a Form 4 is the transaction code, because it separates a real buy from everything that only looks like one. There are three codes you will see constantly.
Code P is an open-market purchase. This is the strongest signal, because the insider reached into their own pocket and paid market price for the shares. When researchers talk about cluster buying by C-suite executives, they are almost always counting P codes.
Code A is an award, usually compensation. These shares are typically granted at a cost of $0 to the insider, so they tell you nothing about whether the executive believes the stock is cheap. Counting awards as buying is the single most common way insider-buying data gets inflated.
Code M is an option exercise. The insider is converting options they already held into shares. That can mean they are buying and holding, but it can also be the first step before selling, so it needs more context before you read anything into it.
How to Read One Without Getting Fooled
Start with the code. If it is not a P, the trade is probably not an independent vote of confidence. Then look at the size relative to the insider’s total holdings and, more usefully, relative to their total compensation. A chief executive buying $1 million of stock at market prices, the kind of trade Michael Brush highlights in his pitch, is a meaningful commitment. The same dollar figure in the form of an annual award is just a paycheck.
The final check is clustering. One insider buying once is noise. Several C-suite executives buying around the same time, at market prices, in meaningful size, is the pattern that insider-buying research treats as a modest positive signal, on the order of 3% to 5% outperformance over six to twelve months. It is a real edge, but a small one, and it works on averages across many names rather than as a guarantee on any single stock.
You can watch these mechanics play out on a live example in our Energy Fuels breakdown, where a chief executive’s roughly $1 million purchase earlier this summer showed up as exactly the kind of P-code filing described above.
Why Footnotes Matter
Below the main table, Form 4s carry footnotes that change what the numbers mean. A footnote might say the shares were held in a trust, or that a portion was sold to cover taxes, or that the “sale” was actually a gift. The best readers treat the footnote as part of the trade, not an appendix. Skipping it is how a routine tax sale gets mistaken for an insider bailing out.
The bottom line
A Form 4 is a small, standardized document that rewards careful reading. The code tells you whether you are looking at a real open-market purchase, an award, or an option exercise. The size and the footnotes tell you how much it means. And the pattern across multiple insiders tells you whether it is worth paying attention to at all. For more on how the broader signal is used across the market, see our insider buying explainer and our insider transactions guide.
Ready to see the research? Click here to access Michael Brush’s report.
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